Abstract:

A cellular communications system may include a cellular base station and
at least one mobile cellular device communicating with the cellular base
station. The at least one mobile cellular device may include a receiver
and a processor cooperating with the receiver for implementing a hybrid
dynamic and static received signal measurement scheduling control. The
processor may include a dynamic scheduler for scheduling recurring
received signal measurement times, a static schedule memory for storing
common data for received signal measurements, and a micro-scheduler for
scheduling received signal measurements based upon the recurring received
signal measurement times and the common data for received signal
measurements.

Claims:

1. A cellular communications system comprising:a cellular base station;
andat least one mobile cellular device communicating with said cellular
base station and comprisinga receiver, anda processor cooperating with
said receiver for implementing a hybrid dynamic and static received
signal measurement scheduling control and comprisinga dynamic scheduler
for scheduling recurring received signal measurement times,a static
schedule memory for storing common data for received signal measurements,
anda micro-scheduler for scheduling received signal measurements based
upon the recurring received signal measurement times and the common data
for received signal measurements.

2. The cellular communications system of claim 1 wherein the received
signal measurements comprise Received Signal Strength Indicator (RSSI)
measurements.

3. The cellular communications system of claim 1 wherein said processor
operates in accordance with a hierarchical protocol layer architecture;
and wherein said dynamic scheduler operates at a higher protocol layer
than said micro-scheduler.

4. The cellular communications system of claim 3 wherein said
micro-scheduler operates at a data link layer.

5. The cellular communications system of claim 1 wherein said at least one
mobile cellular device further comprises a transmitter; and wherein said
processor further comprises an event generator cooperating with said
transmitter, receiver and micro-scheduler to perform the received signal
measurements.

6. The cellular communications system of claim 5 wherein said processor
operates in accordance with a hierarchical protocol layer architecture
including a physical layer; and wherein said event generator operates at
the physical layer.

7. The cellular communications system of claim 5 wherein said
micro-scheduler provides the common data to said event generator using
Direct Memory Access (DMA).

8. The cellular communications system of claim 1 wherein said at least one
mobile cellular communication device further comprises at least one
antenna coupled to said receiver.

9. A mobile cellular device for communicating with a cellular base station
and comprising:a receiver; anda processor cooperating with said receiver
for implementing a hybrid dynamic and static received signal measurement
scheduling control and comprisinga dynamic scheduler for scheduling
recurring received signal measurement times,a static schedule memory for
storing common data for received signal measurements, anda
micro-scheduler for scheduling received signal measurements based upon
the recurring received signal measurement times and the common data for
received signal measurements.

11. The mobile cellular device of claim 9 wherein said processor operates
in accordance with a hierarchical protocol layer architecture; and
wherein said dynamic scheduler operates at a higher protocol layer than
said micro-scheduler.

13. The mobile cellular device of claim 9 further comprising a
transmitter; and wherein said processor further comprises an event
generator cooperating with said transmitter, receiver and micro-scheduler
to perform the received signal measurements.

14. The mobile cellular device of claim 13 wherein said processor operates
in accordance with a hierarchical protocol layer architecture including a
physical layer; and wherein said event generator operates at the physical
layer.

15. A mobile cellular device for communicating with a cellular base
station and comprising:a receiver; anda processor cooperating with said
receiver and operating in accordance with a hierarchical protocol layer
architecture, said processor comprising,a dynamic scheduler for
scheduling recurring received signal measurement times,a static schedule
memory for storing common data for received signal measurements, anda
micro-scheduler for scheduling received signal measurements based upon
the recurring received signal measurement times and the common data for
received signal measurements,said dynamic scheduler operating at a higher
protocol layer than said micro-scheduler.

18. The mobile cellular device of claim 15 further comprising a
transmitter; and wherein said processor further comprises an event
generator cooperating with said transmitter, receiver and micro-scheduler
to perform the received signal measurements.

20. A hybrid dynamic and static received signal measurement scheduling
control method for a mobile cellular device comprising:dynamically
scheduling recurring received signal measurement times;storing common
data for received signal measurements in a static schedule memory;
andscheduling received signal measurements based upon the recurring
received signal measurement times and the common data for received signal
measurements.

22. The method of claim 20 wherein the dynamic scheduling is performed at
a higher protocol layer of a hierarchical protocol layer architecture
than the received signal measurement scheduling.

23. The method of claim 22 wherein the received signal measurement
scheduling is performed at a data link layer.

24. The method of claim 22 further comprising performing the received
signal measurements at a physical layer.

Description:

RELATED APPLICATION

[0001]This application is based upon prior filed copending provisional
application Ser. No. 60/952,610 filed Jul. 30, 2007, the entire subject
matter of which is incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

[0002]The present invention relates to the field of communications
systems, and, more particularly, to cellular communications systems,
devices, and related methods.

BACKGROUND OF THE INVENTION

[0003]Cellular communications systems continue to grow in popularity and
have become an integral part of both personal and business
communications. Cellular phones allow users to place and receive voice
calls most anywhere they travel. Moreover, as cellular telephone
technology has increased, so too has the functionality of cellular
devices. For example, many cellular devices now incorporate personal
digital assistant (PDA) features such as calendars, address books, task
lists, etc. Moreover, such multi-function devices may also allow users to
wirelessly access electronic mail (email) messages and the Internet via a
cellular network.

[0004]With all of the functionality that a user can perform with such
devices, calls made by users, and the overhead operations required of the
device, battery life may be a significant concern for cellular phone
manufacturers. For example, the Global System for Mobile communication
(GSM)/Enhanced Data rates for Global Evolution (EDGE) and Universal
Mobile Telecommunications System (UTMS) (i.e., 3G) systems require
handsets to perform measurements of Receive Signal Strength Indication
(RSSI) of neighboring base station on a periodic basis (e.g., every 30
seconds). These operations are even required when a device is in a
"sleep" or power saving mode.

[0005]Various approaches have been implemented for attempting to reduce
power consumption in mobile cellular devices. For example, U.S. Pat. No.
6,002,918 to Heiman et al. discloses a communications network including a
cellular local area wireless network which includes a plurality of access
points connected to a housed computer and each other, and a plurality of
mobile units. Each mobile unit is arranged for association with an access
point. The mobile units are also arranged to periodically scan for and
identify the most eligible access point for association on the basis of
the criteria of best quality signal strength and loading factor. To
identify when mobile units are being removed from a predetermined area,
access points having directional antennae are situated adjacent exit
points to detect when mobile units are in a vicinity. Each mobile unit
may include paging facilities, including the capability of transmitting
information in a coded form known both to the unit and to a host, and
power-saving facilities.

[0006]Despite the existence of such systems, further approaches and
techniques for mitigating the power consumption of handheld device
operations may be desirable to extend mobile device battery life.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007]FIG. 1 is a schematic block diagram of a cellular communications
system in accordance with one aspect.

[0008]FIG. 2 is a schematic block diagram of the mobile cellular device
processor of FIG. 1 in accordance with one exemplary embodiment.

[0009]FIG. 3 is a flow diagram of a hybrid dynamic/static receive signal
measurement scheduling method in accordance with one embodiment.

[0010]FIG. 4 is a schematic block diagram illustrating exemplary
components which may be included in the mobile cellular device of FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011]The present description is made with reference to the accompanying
drawings, in which preferred embodiments are shown. However, many
different embodiments may be used, and thus the description should not be
construed as limited to the embodiments set forth herein. Rather, these
embodiments are provided so that this disclosure will be thorough and
complete. Like numbers refer to like elements throughout.

[0012]Generally speaking, a cellular communications system is disclosed
herein which may include a cellular base station and at least one mobile
cellular device communicating with the cellular base station. More
particularly, the at least one mobile cellular device may include a
receiver and a processor cooperating with the receiver for implementing a
hybrid dynamic and static received signal measurement scheduling control.
The processor may include a dynamic scheduler for scheduling recurring
received signal measurement times, a static schedule memory for storing
common data for received signal measurements, and a micro-scheduler for
scheduling received signal measurements based upon the recurring received
signal measurement times and the common data for received signal
measurements.

[0013]By way of example, the received signal measurements may be Received
Signal Strength Indicator (RSSI) measurements. Additionally, the
processor may operate in accordance with a hierarchical protocol layer
architecture, and the dynamic scheduler may operate at a higher protocol
layer than the micro-scheduler. The micro-scheduler may operate at a data
link layer, for example.

[0014]The at least one mobile cellular device may further include a
transmitter, and the processor may further include an event generator
cooperating with the transmitter, receiver and micro-scheduler to perform
the received signal measurements. Moreover, the event generator may
operate at the physical layer. Additionally, the micro-scheduler may
provide the common data to the event generator using Direct Memory Access
(DMA), for example. The at least one mobile cellular communication device
may also include at least one antenna coupled to the receiver.

[0015]A mobile cellular communications device, such as the one described
briefly above, and a hybrid dynamic and static received signal
measurement scheduling control method for a mobile cellular device are
also provided. The method may include dynamically scheduling recurring
received signal measurement times, storing common data for received
signal measurements in a static schedule memory, and scheduling received
signal measurements based upon the recurring received signal measurement
times and the common data for received signal measurements.

[0016]Referring initially to FIGS. 1 and 2, a cellular communications
system 30 illustratively includes a cellular base station 31 and one or
more mobile cellular devices 32 communicating with the cellular base
station. The mobile cellular device 32 illustratively includes a receiver
33 and associated antenna 34, and a processor 35 cooperating with the
receiver for implementing a hybrid dynamic and static received signal
measurement scheduling control, as will be discussed further below. The
processor 35 further illustratively includes a dynamic scheduler 36 for
scheduling recurring received signal measurement times, such as Receive
Signal Strength Indication (RSSI) measurements, a static schedule memory
37 for storing common data for received signal measurements, and a
micro-scheduler 38 for scheduling received signal measurements based upon
the recurring received signal measurement times and the common data for
received signal measurements.

[0017]The micro-scheduler 38 may advantageously schedule and keep track of
when certain cellular network operations are to be performed, such as the
above-described RSSI measurements. The micro-scheduler preferably 38
operates at a lower protocol layer of a hierarchical protocol layer
architecture (e.g., OSI protocol) than the dynamic scheduler 36, such as
the data link layer, and retrieves schedule information from the dynamic
scheduler via a dynamic schedule memory 40. The dynamic scheduler 36
operates in an upper protocol layer(s), such as an application layer, for
example. Thus, in the present example, the dynamic scheduler 36 generates
the recurring RSSI measurement start times, although other received
signal recurring scheduling information may also be generated by the
dynamic scheduler, as will be appreciated by those skilled in the art.

[0018]A timing control unit (TCU)/event generator 41 (FIG. 2) is also
illustratively included at the physical layer for interfacing with the
cellular network (i.e., the cellular base station 31) to coordinate
communications to within appropriate network timing slots, as will be
appreciated by those skilled in the art. It will also be appreciated that
the dynamic scheduler 36, micro-scheduler 38, TCU/event generator 41,
and/or memories 37, 41 may be implemented using a combination of hardware
and/or software components. Moreover, the memories 37, 40 need not be
separate memory devices in all embodiments, but instead could merely be
partitions of a same memory device. Other exemplary components which may
be included in such a wireless communications device are described
further below with reference to FIG. 4.

[0019]By way of comparison, in a typical prior art implementation a
processing module (e.g., a digital signal processor (DSP) or other
processor) creates physical control schedules during run time for the
network communication operations as they come due. Such scheduling
operations may conceptually be considered as dynamic scheduling, as new
schedules are continuously being created. These schedules are typically
either erased from memory or overwritten in memory as they are completed,
and new schedules are generated to thereby save on memory consumption.

[0020]Such a prior art dynamic schedule control process creates (and
re-creates) all of the control schedules during run time, which takes
time, power, and resources from the processor. This can be problematic in
that, even when the device is in a "sleep" mode with its LCD screen
turned off, constantly re-creating schedules for RSSI checks every thirty
seconds or so still consumes a significant amount of battery resources
due to the processor and bus resources that are used.

[0021]Yet, in accordance with the present embodiment, scheduling
information or data that is common (i.e., substantially identical or
unchanged) from one RSSI measurement to the next is separated from the
processing operations of the dynamic scheduler 36, and this common or
static information is instead stored in the static schedule memory 37. As
such, the dynamic scheduler 36 therefore typically only needs to update
the recurring start times for the next (i.e., upcoming) RSSI measurement
operations.

[0022]This hybrid approach between static and dynamic scheduling control
may be used to advantageously reduce the amount of processing time, and
therefor power consumption, used for generating and implementing RSSI and
other control schedules, as will be appreciated by those skilled in the
art. Considered alternatively, the RSSI scheduling operations are
implemented using static control such that the building blocks of the
schedules are static, and the required blocks are called from the static
schedule memory 37 at run time.

[0023]Referring now additionally to FIG. 3, one exemplary implementation
of a hybrid dynamic/static scheduling method is now described. Beginning
at Block 50, upon start-up (Block 52) the dynamic scheduler 36 may
initially generate the common data associated with the RSSI control
schedules, at Block 54, which is stored in the static schedule memory
(e.g., in a look-up table (LUT)) for future reference (Block 56). Rather
than re-generating this common schedule information every thirty seconds
or so, the micro-scheduler 38 simply refers to the look-up table every
RSSI detection period as needed, at Block 38.

[0024]With the common schedule data for RSSI measurements already in the
static schedule memory 37, all that remains is to send the schedule to
the TCU/event generator 41 based upon the RSSI measurement start times
scheduled by the dynamic scheduler 36 (Block 60). The TCU/event
controller 41 cooperates with the micro-scheduler 38 to process the
schedules at the correct time, and activate only the components of the
mobile cellular device 34 that are required (e.g., the receiver 33,
transmitter, etc.). This advantageously saves schedule building time
(power) as well as processor run time (resources/power). Direct Memory
Access (DMA) or other suitable methods may be used to send the common
schedule data that is already in the static schedule memory 37 to the
TCU/event generator 41, for example, although other suitable approaches
may also be used.

[0025]While the individual power savings for a given RSSI schedule
processing operation may be relatively small, over time the cumulative
effects of such repetitive processing operations can result in a
significant power drain, particularly when the mobile cellular device 30
is in sleep mode (less power savings may be achieved in "wake" or normal
mode where the device is already performing processing operations and/or
the RE circuitry is already in use due to a telephone call, etc.). That
is, during sleep mode every microsecond counts toward extending battery
life. Another advantage of the hybrid static/dynamic control approach is
that this may reduce the time that other dynamic scheduling operations
have to wait for available processing resources.

[0026]Accordingly, the above-described scheduling approach is particularly
advantageous for reducing the work (i.e., processing operations) a mobile
cellular device needs to do to schedule an event that repeats on a
regular bases, such as RSSI measurements. This is achieved by storing in
the static schedule memory 37 (e.g., in LUT format) the
instruction/timing event for measurement, and loading these instructions
into the TCU/event generator 38 as needed. It should be noted that this
approach may be used with other operations besides received signal/RSSI
measurement scheduling that repeat on a regular or periodic basis, as
will be appreciated by those skilled in the art.

[0027]The above-described approach advantageously has the benefit of
reducing the time the RF front end is turned on, not only in the sleep
mode but also in normal operating mode as well. In some embodiments, the
physical layer/RF control may run on a DSP. The remaining portions of the
processor 35 may be implemented using the DSP and/or microprocessor of
the mobile cellular device 30, for example. The above-noted approach is
particularly well suited to GSM/GPRS/EDGE implementations (especially in
extended dynamic allocation required for class 12 and higher devices),
though it may be used in accordance with other cellular protocols (e.g.,
3G) as well, as will be appreciated by those skilled in the art.

[0028]Exemplary components which may be used in the mobile cellular device
30 are now described with reference to a hand-held mobile wireless
communications device 1000 illustrated in FIG. 4. The device 1000
illustratively includes a housing 1200, a keypad 1400 and an output
device 1600. The output device shown is a display 1600, which is
preferably a full graphic LCD. Other types of output devices may
alternatively be utilized. A processing device 1800 is contained within
the housing 1200 and is coupled between the keypad 1400 and the display
1600. The processing device 1800 controls the operation of the display
1600, as well as the overall operation of the mobile device 1000, in
response to actuation of keys on the keypad 1400 by the user.

[0029]The housing 1200 may be elongated vertically, or may take on other
sizes and shapes (including clamshell housing structures). The keypad may
include a mode selection key, or other hardware or software for switching
between text entry and telephony entry.

[0030]In addition to the processing device 1800, other parts of the mobile
device 1000 are shown schematically in FIG. 4. These include a
communications subsystem 1001; a short-range communications subsystem
1020; the keypad 1400 and the display 1600, along with other input/output
devices 1060, 1080, 1100 and 1120; as well as memory devices 1160, 1180
and various other device subsystems 1201. The mobile device 1000 is
preferably a two-way RF communications device having voice and data
communications capabilities. In addition, the mobile device 1000
preferably has the capability to communicate with other computer systems
via the Internet.

[0031]Operating system software executed by the processing device 1800 is
preferably stored in a persistent store, such as the flash memory 1160,
but may be stored in other types of memory devices, such as a read only
memory (ROM) or similar storage element. In addition, system software,
specific device applications, or parts thereof, may be temporarily loaded
into a volatile store, such as the random access memory (RAM) 1180.
Communications signals received by the mobile device may also be stored
in the RAM 1180.

[0032]The processing device 1800, in addition to its operating system
functions, enables execution of software applications 1300A-1300N on the
device 1000. A predetermined set of applications that control basic
device operations, such as data and voice communications 1300A and 1300B,
may be installed on the device 1000 during manufacture. In addition, a
personal information manager (PIM) application may be installed during
manufacture. The PIM is preferably capable of organizing and managing
data items, such as e-mail, calendar events, voice mails, appointments,
and task items. The PIM application is also preferably capable of sending
and receiving data items via a wireless network 1401. Preferably, the PIN
data items are seamlessly integrated, synchronized and updated via the
wireless network 1401 with the device user's corresponding data items
stored or associated with a host computer system.

[0033]Communication functions, including data and voice communications,
are performed through the communications subsystem 1001, and possibly
through the short-range communications subsystem. The communications
subsystem 1001 includes a receiver 1500, a transmitter 1520, and one or
more antennas 1540 and 1560. In addition, the communications subsystem
1001 also includes a processing module, such as a digital signal
processor (DSP) 1580, and local oscillators (LOs) 1601. The specific
design and implementation of the communications subsystem 1001 is
dependent upon the communications network in which the mobile device 1000
is intended to operate. For example, a mobile device 1000 may include a
communications subsystem 1001 designed to operate with the Mobitex®,
Data TAC® or General Packet Radio Service (GPRS) mobile data
communications networks, and also designed to operate with any of a
variety of voice communications networks, such as AMPS, TDMA, COMA,
WCDMA, PCS, GSM, EDGE, etc. Other types of data and voice networks, both
separate and integrated, may also be utilized with the mobile device
1000. The mobile device 1000 may also be compliant with other
communications standards such as 3GSM, 3GPP, UMTS, etc.

[0034]Network access requirements vary depending upon the type of
communication system. For example, in the Mobitex and DataTAC networks,
mobile devices are registered on the network using a unique personal
identification number or PIN associated with each device. In GPRS
networks, however, network access is associated with a subscriber or user
of a device. A GPRS device therefore requires a subscriber identity
module, commonly referred to as a SIM card, in order to operate on a GPRS
network.

[0035]When required network registration or activation procedures have
been completed, the mobile device 1000 may send and receive
communications signals over the communication network 1401. Signals
received from the communications network 1401 by the antenna 1540 are
routed to the receiver 1500, which provides for signal amplification,
frequency down conversion, filtering, channel selection, etc., and may
also provide analog to digital conversion. Analog-to-digital conversion
of the received signal allows the DSP 1580 to perform more complex
communications functions, such as demodulation and decoding. In a similar
manner, signals to be transmitted to the network 1401 are processed (e.g.
modulated and encoded) by the DSP 1580 and are then provided to the
transmitter 1520 for digital to analog conversion, frequency up
conversion, filtering, amplification and transmission to the
communication network 1401 (or networks) via the antenna 1560.

[0036]In addition to processing communications signals, the DSP 1580
provides for control of the receiver 1500 and the transmitter 1520. For
example, gains applied to communications signals in the receiver 1500 and
transmitter 1520 may be adaptively controlled through automatic gain
control algorithms implemented in the DSP 1580.

[0037]In a data communications mode, a received signal, such as a text
message or web page download, is processed by the communications
subsystem 1001 and is input to the processing device 1800. The received
signal is then further processed by the processing device 1800 for an
output to the display 1600, or alternatively to some other auxiliary I/O
device 1060. A device user may also compose data items, such as e-mail
messages, using the keypad 1400 and/or some other auxiliary I/O device
1060, such as a touchpad, a rocker switch, a thumb-wheel, or some other
type of input device. The composed data items may then be transmitted
over the communications network 1401 via the communications subsystem
1001.

[0038]In a voice communications mode, overall operation of the device is
substantially similar to the data communications mode, except that
received signals are output to a speaker 1100, and signals for
transmission are generated by a microphone 1120. Alternative voice or
audio I/O subsystems, such as a voice message recording subsystem, may
also be implemented on the device 1000. In addition, the display 1600 may
also be utilized in voice communications mode, for example to display the
identity of a calling party, the duration of a voice call, or other voice
call related information.

[0039]The short-range communications subsystem enables communication
between the mobile device 1000 and other proximate systems or devices,
which need not necessarily be similar devices. For example, the
short-range communications subsystem may include an infrared device and
associated circuits and components, or a Bluetooth® communications
module to provide for communication with similarly-enabled systems and
devices.

[0040]Many modifications and other embodiments will come to the mind of
one skilled in the art having the benefit of the teachings presented in
the foregoing descriptions and the associated drawings. Therefore, it is
understood that various modifications and embodiments are intended to be
included within the scope of the appended claims.